Читать книгу Essentials of Nuclear Medicine Physics, Instrumentation, and Radiation Biology - Rachel A. Powsner - Страница 15

In our simple solar‐system model of the atom, the electrons are viewed as orbiting the nucleus at high speeds. They have a negative charge and the nucleus has a positive charge. The electrical charges of the atom are “balanced,” that is, the total negative charge of the electrons equals the positive charge of the nucleus. As we shall see in a moment, this is simply another way to point out that the number of orbital electrons equals the number of nuclear protons.